diagnostics: convert enum logical_location_kind to enum class

diagnostics: convert enum logical_location_kind to enum class

No functional change intended.

gcc/ChangeLog:
	* diagnostic-format-sarif.cc (maybe_get_sarif_kind): Update for
	conversion of enum logical_location_kind to enum class.
	* diagnostic.cc (logical_location_manager::function_p): Likewise.
	* libgdiagnostics.cc (html-output/missing-semicolon.py::get_kind):
	Likewise.
	* logical-location.h (enum logical_location_kind): Convert to...
	(enum class logical_location_kind): ...this.
	* selftest-logical-location.cc
	(test_logical_location_manager::item_from_funcname): Update for
	conversion of enum logical_location_kind to enum class.
	* tree-logical-location.cc
	(tree_logical_location_manager::get_kind): Likewise.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>